Steam-boiler furnace



(No Model.)

J. ANDERSON.

STEAM BOILBR PURNAGB.

Patented Mar. 29, 1.887.

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UNITED STATES PATENT OFFICE.

JOSEPH ANDERSON, OF PITTSBURG, PENNSYLVANIA.

STEAM-BOILER FURNACE.

SPECIFICATION forming part of Letters Patent No. 360,079, dated March 29, 1887.

Application filed December 10, 1884. Serial No. 149,939. (Xo lnmhl.)

To all whom, t may concern.-

Be it known that I, JOSEPH ANDERSON, of the city of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Steam-Boiler Furnaces; and I do hereby declare the following to be a full, clear, and exact description thereof, reference being had to the accompanying drawings, in which Figurel is a side elevation of a steanrboiler, partly in section, illustrating my improvement. Fig. 2 is a sectional plan View on the line :r fr of Fig. l. Fig. 8 is a front elevation of Fig. l, the latter beinga verticallongitudinal section on the linee z of this figure.

Like letters of reference indicate like parts.

My improvement relates to the construction and arrangementof a furnace in which the air for supporting combustion is heated bythe products of combustion from the furnace before it is introduced into the fire-chamber.

I will now describe my invention with reference to a furnace in which gaseous fuel is used; but it applies equally to every description of furnace, whatever kind of fuel it may be adapted to, whether gaseous or solid.

In the drawings, a represents steam-boilers of the usual construction having the ordinary longitudinal flues, l) b. Thegas is introduced -into a closed chamber, c, through a perforated T-burner, d, arranged t-herein, and deriving its gas from a supply-pipe, d', which enters the wall of the chamber. rlhe gas ignites in this chamber, and the burning gas and heated products pass over the bridge-wall e, along the bottom of the boiler to its rear end, thence back again through the flues b b tothe staekf.

Above-the boilers is a chamber, h, which eX- tends the entire length of the boilers, and is preferably made with brick walls, as shown in the drawings. IVithin the chamber is a iiue, ifi', which enters at the front end and extends to the rear, where it is retleXed, and extends again to and outside of the front end of the chamber. Both ends of the flue Ii yi are open and communicate with the stack, the lower branch, 2', communicating with the chamber f which is formed by the usual stack-skirt, which receives the smoke from the boiler-fines, and the upper branch, z", communicating with the stack proper, f. A partition, f2, is arranged in the stack between the openings of the blanches@v i of the flue, so as to shut off all direct communication between the skirt-chamber and the rest of the stack. The heated products of combustion from the boiler-fines I) b, after passing into the chamberf, are thus obliged to enter the mouth of the flue i i', and to pass therethrough in a circuitous course to the stack fabove the partition f2. In their passage they raise the flue and the surrounding air in the chamber h to a considerable degrec of heat.

|Ihe chamber It is closed, except lthat at the rear end is an air port or opening, h', and at the side of the chamber, near the front end, is another opening, from which a pipe, h2, leads to the combustion-chamber c, the outlet ofthe pipe h2 being just underneath the gas-burner el.

The combustionchamber is closed, so that all the air for combustion of the gas must be drawn from the air-chamber h through the pipe hi. The air thus removed from the chamber hI is supplied by air entering the opening 7L', and in this manner there is a continuous circulation of air through this chamberaround the flue-pipes i t" and down the pipe h2 to the combustion-chamber. The contact with the flue i i,and with the surface ofthe boiler within the chamber, is sufficient to heat the air enough to economize fuel and to increase the capacity of the furnace very largely.

In addition to utilizing the waste products of the furnace for heating the air, an advantage of my improvement is that the chamber h acts as a non-conducting covering for the boiler,

because it is in juxtaposition to the top thereof, and is continually filled with heated air.

In -case of the application of my improvement to a battery of more than one boiler the chamber 7L may be made to cover all the boilers, or there may be a separate chamber for each boiler, as desirable. In either ease the most convenient way of constructingthe chainber is to extend the brick walls m of the boiler structure upward to the required distance above the boiler level, connecting them by an arch or roof, m. The top of the boiler or boilers will then form the bottom of the chamber 71, and will aid in heating the air by radiation from the steam.

I am aware that furnaces in which air is l OCI heated by the products of combustion and conducted to the fire-chamber are not new, and `I do not desire to claim the same, broadly.

What I claim as my invention, and desire to secure by Letters Patent, is

In a boiler-furnace, the combination of a eombustionchamber, and boiler-lues for the passage of the products of combustion which pass under the boiler to the rear thereof and thence through the flues to the front of the boiler, a connecting-chamber7 f', situate at the front ofthe boiler and communicating with the boiler-fines, a heatingohaniber, 7L, overlying the boiler, a stack, a recurrentflue, i i', arranged in the heating-chamber h., co mlnunicatingat one end with the ohamberf and at the other end with the stack, au air-adit port in the heating-chamber h, and a conducting pipe or fluerhz, leading from the heating-chamber to the combustion-chamber, whereby the products of combustion passing from the boilerlues and connecting-chambery through the flue i z" into the stack heat the air which enters the air-adit port and circulates around the recurrent ue i i in the heating-charnber h, finally entering the combustion-chamber through the conducting pipe or flue hz, substantially as and for the purposes described.

In' testimony whereof I have hereunto set my hand this 2d day of December, A. D. 1884.

JOSEPH ANDERSON. Vitnesses:

THOMAS WV. BAKEWEL'L, W. B. CORWIN. 

